Multi-analyte high performance liquid chromatography coupled to high resolution tandem mass spectrometry method for control of pesticide residues,mycotoxins, and pyrrolizidine alkaloids

A new reliable and highly sensitive method based on high performance liquid chromatographic (HPLC) separation and high resolution tandem mass spectrometric detection (HRMS/MS) has been developed and validated for determination of 323 pesticide residues, 55 mycotoxins, and 11 plant toxins represented by pyrrolizidine alkaloids. The method was validated for three matrices, leek, wheat, and tea differing in nature/amount of co-extracts that may cause various matrix effects. For target analytes isolation, optimized QuEChERS-based (quick, easy, cheap, effective, rugged, and safe) extraction procedure was employed. Spectral HRMS/MS library has been established providing an entire spectrum of fragment ions for each analyte, which allows unbiased identification and confirmation of target compounds. The limits of quantification (LOQs) of target analytes were below 10 μg kg⁻¹ for 82%, 81%, and 61% for matrices leek, wheat, and tea, respectively. Recoveries were in the acceptable range (70–120%) according to SANCO/12571/2013 for most of target analytes, except for highly polar ‘masked’ mycotoxin deoxynivalenol-3-glucoside with recoveries 35%, 47%, and 42% for matrices leek, wheat, and tea, respectively. The linearities of calibration curves expressed as coefficients of determination were in the range of 0.9661–1.000, and repeatabilities expressed as relative standard deviations (RSDs) at LOQs lied in the range of 0.25–13.51%. The trueness of the method was verified using several certified reference materials (CRMs) and proficiency test samples.     

芦苇秆粉末的热脱附-气相色谱/质谱分析

采用热脱附-气相色谱/质谱联机技术（TD-GC/MS）分析了芦苇杆粉末在不同环境温度下的挥发物释放行为。结果表明：芦苇杆粉末在40℃及160℃的挥发物中,主要有益成分分别为主要有害成分的4.43倍和5.13倍,环境友好性良好;在60℃及90℃的挥发物中,主要有益成分比例也比主要有害成分高,90℃时的有益成分为有害成分的2.45倍,环境友好性较好。以芦苇杆粉末为基材,在木质素软化温度点和木质材料碳化温度点之间（150—180℃）实施高压无胶模塑成形工艺制备木质粉末基复合材料必将体现出良好的环境友好性。     

安徽省泗县池塘底泥As含量分布特征及污染评价

利用X射线荧光光谱法测定了安徽泗县池塘底泥中As的含量,探讨其分布特征及来源并进行生态风险评价。结果表明:研究区池塘底泥As含量的变化范围在8—26mg/kg,平均值为13.32mg/kg;空间分布为:新集>黄圩>杨集>武圩>大庄>中心区;工业废弃物的排放以及含As养殖饲料的使用对底泥As富集的贡献显著;As的地累积指数(Igeo)范围在-0.66—1.05,为无污染到中度污染。长远来看,As累积趋势的存在,对土壤质量和农业安全生产具有一定的隐患。     

南方某县乡镇饮用水中挥发性有机物的检测及风险评价

在南方某癌症高发县5个乡镇10个村进行布点取样,采集深层地下水与浅层地下水共计20个水样。采用吹扫捕集与气相色谱-质谱联用方法测定水样中13种挥发性有机物(VOCs),检出二氯甲烷、三氯甲烷、苯和四氯化碳4种VOCs,其浓度分别为0.36—13.52、0.41—18.71、0.57—11.75μg/L和1.56—214.62μg/L。1个水样中苯和16个水样中四氯化碳超过GB 5749-2006规定的限值。采用优化的USEPA风险评价模型,对VOCs进行人体健康风险评价,其非致癌风险指数0.0073—0.7100,致癌风险水平1.98×10-6—1.99×10-4,全部水样的致癌风险水平超过10-6水质监控值,1个水样的致癌风险水平超过10-4的可接受水平。四氯化碳对非致癌风险指数和致癌风险水平贡献最大。     

基于特征选择的网络入侵检测模型研究

为了有效从收集的恶意数据中选择特征去分析,保障网络系统的安全与稳定,需要进行网络入侵检测模型研究。但目前方法是采用遗传算法找出网络入侵的特征子集,再利用粒子群算法进行进一步选择,找出最优的特征子集,最后利用极限学习机对网络入侵进行分类,但该方法准确性较低。为此,提出一种基于特征选择的网络入侵检测模型研究方法。该方法首先以增强寻优性能为目标对网络入侵检测进行特征选择,结合分析出的特征选择利用特征属性的Fisher比构造出特征子集的评价函数,然后结合计算出的特征子集评价函数进行支持向量机完成对基于特征选择的网络入侵检测模型研究方法。仿真实验表明,利用支持向量机对网络入侵进行检测能有效地提高入侵检测的速度以及入侵检测的准确性。     

红外热成像辅助面神经功能自动评估方法研究

面瘫是一种多发的面神经疾病,表现为患侧面神经功能失调,严重影响患者的正常生活和人际交往。面神经功能自动评估方法对于面瘫的诊治是至关重要的。面部神经功能受损导致体表温度分布发生改变,可以通过红外热成像采集患者的面部温度分布不对称特征,基于红外热成像提出一种面神经功能自动评估新方法,融合温度特异性和边缘检测自动将面部红外热像划分为左右对称的八个区域,提取面部温度不对称特征,包括温差、有效热面积比和温度分布不对称度,采用径向基神经网络作为面神经功能自动分类器。实验收录了390幅单侧患病的面瘫患者正面红外热像图,结果显示：采用径向基神经网络的红外热成像面神经功能自动分类器的平均分类准确率为94.10%,比采用K近邻分类器和支持向量机分类器分别提高了9.31%和4.87%,优于传统的House-Brackmann面神经功能评估方法,对面神经功能的分类精度完全符合临床应用标准,可以有效评估面瘫患者的面神经功能,有助于面瘫的临床诊断与治疗。     

Mass and energy flow management in the sector of surface treatment

Vehicle refinishing body shops are concerned by the environmental policy against photochemical air pollution caused by VOC emissions. For supporting these small enterprises the mass and energy flow model IMPROVE has been developed. Based on an LCA-approach, the process steps of vehicle refinishing are modelled. The model IMPROVE helps to disseminate the consequences of product substitution in comparison to so far used products and techniques in the body shop. For the dissemination of experiences practical guidelines have been developed. Moreover, a comprehensible tool for the Solvent Balance is being offered. Thus, various means are available for consulting and also for strategic production planning for the SME in the sector.     

宿州城市土壤重金属污染特征及其健康风险评价

选取宿州市不同功能区(工业区、商业区、车站附近、居民区以及城市绿地)采集表层土壤样品55个,利用XRF测定出土壤中重金属Cu、Zn、Pb、Cr、Mn、Ni的含量,并借助健康风险评价模型,分别评价了土壤重金属在不同暴露途径下的健康风险。结果表明,Cu、Zn、Pb和Cr的平均含量均超出安徽省土壤背景值,说明宿州城市土壤中已受到不同程度的重金属污染;工业区、商业区和车站附近土壤重金属含量普遍较高,Cu、Zn、Pb与交通运输、工业生产关系密切,Cr主要来源于工业废弃物排放,Ni则受到生活污染和交通污染的双重影响;土壤重金属的非致癌风险指数(HI)和致癌风险指数(Risk)均低于危害水平界限,未形成明显的健康风险。     

Green chemistry: Analytical and chromatography

Nowadays, the environment protection and the personal health and safety are given more consideration in the field of chemistry, thus resulting in an increased number of published researches about how to work according to green instructions, to follow up the recommendations of environmental agencies and to obtain better clean handling of chemistry. In this review, green chemistry definition, importance, principles, and some recent applications in the field of green chemistry were discussed. In addition, the review summarizes the evolution of green analytical chemistry (GAC) with its specific principles and how to make the analytical process more environmentally benign with special emphasis on recent applications of GAC. Moreover, the green chromatography, its methods, and some of its applications were outlined. Finally, different techniques available up till now for the assessment of greening of the methods were also presented.     

立体声纵论

本文提出了立体声的科学分类和质量评价一种方法，并分析了数学信号处理技术的引入对立体声所产生的飞跃和问题。